Method for manufacturing a surgical device for extracting a foreign object

Abstract

A method for manufacturing the surgical device for removing a foreign object from a body and a retrieval basket of the device are described. The retrieval basket is adapted for entrapping and retaining the object located in the body. The basket comprises a structure having a proximal end and a distal end. The structure is formed by a plurality of filaments fabricated from a single or several wires. The filaments extend from the proximal end towards the distal end, and are bound together to define a plurality of strands. The strands ramify at corresponding branching points into loops having various shapes and sizes. At least a part of the loops are overlapped and/or interlaced so as to define a net, and thereby impart structural rigidity and dilatation ability to the basket when opened. The method of manufacturing the retrieval basket includes selecting at least one wire; weaving the basket from the wire by overlapping and/or interlacing the filaments so that to form a net at least in the vicinity of the distal end; and binding the filaments for forming a shape of the retrieval basket.

1. A method for manufacturing a retrieval basket having a proximal end and a distal end and constituted by a plurality of wire filaments extending from the proximal end towards the distal end, comprising:
 selecting at least one wire; 
 weaving the basket from the wire, wherein said weaving includes forming portions from wire filaments that are bound together to define a plurality of strands, said plurality of strands ramify at corresponding branching points into loops having various shapes and sizes, at least a part of the loops are overlapped and/or interlaced at spaced points so as to define a net at least in the vicinity of, and spaced from the distal end; and 
 forming a shape of the retrieval basket, thereby imparting structural rigidity and dilatation abilities to the basket when opened. 
 
     
     
       2. The method of  claim 1  further including binding the strands together at said proximal end for forming a manipulation cable. 
     
     
       3. The method of  claim 2  further including binding the filaments of the manipulation cable by temporary bushings. 
     
     
       4. The method of  claim 3  further including annealing said retrieval basket. 
     
     
       5. The method of  claim 1  including binding the filaments at the distal end together for forming a basket tip. 
     
     
       6. The method of  claim 4  wherein the wire is made of metallic material. 
     
     
       7. The method of  claim 6  wherein said metallic material has thermo- mechanical shape memory characteristic. 
     
     
       8. The method of  claim 6  wherein said metallic material has supereleastic characteristic. 
     
     
       9. The method of  claim 6  wherein said metallic material is selected from NiTi based alloy and stainless steel. 
     
     
       10. The method of  claim 9  wherein said annealing is carried out at the temperature in the range of about 450° C. - 600° C. 
     
     
       11. The method of  claim 1  wherein said forming of the shape includes preparing a shape-forming jig having a predetermined shape. 
     
     
       12. The method of  claim 11  wherein said forming of the shape includes binding the filaments and the strands on said shape-forming jig. 
     
     
       13. The method of  claim 12  wherein said forming of the shape further includes annealing said retrieval basket. 
     
     
       14. The method of  claim 1  wherein said weaving includes preparing a weaving jig having a predetermined a pattern formed by grooves configured on a surface of the jig. 
     
     
       15. The method of  claim 14  wherein at least a part of the weaving of the basket is performed on said weaving jig, wherein said weaving includes
 fixing one end of the wire, while the other end is putting on the top part of the jig; and 
 moving the free end along the grooves by taking it away from the jig and returning it thereto together with overlapping and/or interlacing the wire filaments, in accordance with a desired pattern of the weaving and topology of the basket structure. 
 
     
     
       16. The method of  claim 1  wherein said weaving of the basket includes:
 selecting a predetermined number of wires; 
 joining the wires together in a bunch; 
 fixing a bushing on the bunch at a predetermined distance from an end of the bunch; 
 overlapping and/or interlacing the wire filaments so that to form a net; 
 fixing another bushing on the bunch, thereby to avoid unweaving of the net. 
 
     
     
       17. The method of  claim 16  further including a step of forming a guide rod that includes cutting of a certain number of the wire filaments at the distal end; and twisting the remaining number of the filaments together. 
     
     
       18. The method of  claim 1  wherein the filaments in a region of the structure at the proximal end form a plurality of strands, where one of the strands is common for all the filaments. 
     
     
       19. The method of  claim 1  wherein said shape is a parachute-like shape. 
     
     
       20. The method of  claim 1  wherein said shape is a spoon-like shape. 
     
     
       21. The method of  claim 1  wherein the wire are made of non-metallic material. 
     
     
       22. The method of  claim 21  wherein said non-metallic material is Capron. 
     
     
       23. The method of  claim 1  wherein the filaments are covered by a coating layer. 
     
     
       24. The method of  claim 23  wherein said coating layer is made of Teflon. 
     
     
       25. A method of manufacturing a surgical device for removing a foreign object from a body, comprising:
 providing a retrieval basket fabricated according to  claim 1  configured for entrapping and retaining the object located in the body for its extraction therefrom; 
 providing a basket control assembly comprising a tubular sheath adapted to penetrate into the body for reaching the object, a manipulator for manipulating the basket for extraction the object from the body, and a manipulation cable arranged within the sheath for connecting the basket to the manipulator, where the assembly is configured for retracting the basket within the sheath and protracting the basket therefrom for its opening; and 
 coupling the retrieval basket to the basket control assembly. 
 
     
     
       26. The method of  claim 25  wherein said manipulation cable is constituted by said plurality of filaments extending from said proximal end towards the manipulator. 
     
     
       27. The method of  claim 25  further comprising the step of providing a filling tubing and putting thereof at least on a portion of said manipulation cable. 
     
     
       28. The method of  claim 27  wherein a magnitude of diameter of said filling tubing is sufficient to fill a gap between an inner wall of the catheter and the manipulation cable. 
     
     
       29. The method of  claim 25  wherein said manipulation cable is configured as a separaLe unit selected from a rod, cable and wire. 
     
     
       30. The method of  claim 29  wherein a joint between a common basket strand of the basket and the manipulation cable is established by means of a bushing. 
     
     
       31. The method of  claim 30  wherein at least a portion of said manipulation cable has a magnitude of diameter sufficient to substantially eliminate any gap between an inner wall of the catheter and the manipulation cable. 
     
     
       32. The method of  claim 30  wherein a magnitude of diameter of the bushing and a magnitude of diameter of at least a portion of said manipulation cable are close to one another.